In a Survey, 20 People Were Asked How Many Magazines $$\begin{array} { r r r r r r r r r r } 6 & 15 & 3 & 36 & 25 & 18 & 12 & 18 & 5 & 30 \\24 & 7 & 0 & 22 & 33 & 24 & 19 & 4 & 12 & 9\end{array}$$

Essay

In a survey, 20 people were asked how many magazines they had purchased during the previous year. The results are shown below. Construct a histogram to represent the data.
Use 4 classes with a class width of 10, and begin with a lower class limit of -0.5. What is the approximate amount at the center? $$\begin{array} { r r r r r r r r r r } 6 & 15 & 3 & 36 & 25 & 18 & 12 & 18 & 5 & 30 \\24 & 7 & 0 & 22 & 33 & 24 & 19 & 4 & 12 & 9\end{array}$$